I wonder if Mark was referring to the birds weight rather than the bubbled one.
The bubbled ones were made by Cristallerie Schneider, the post war company set up by Charles Schneider. These items were referred to as "crystal balls" not paperweights. And it has been suggested that Cristallerie Schneider was "the first, even before Daum, to launch the vogue for crystal balls". Info from the book, Schneider by Edith Mannoni.